Terminal connector and guard assembly



Feb. 13, 1962 E. .ALEHMAN TERMINAL CONNECTOR AND GUARD ASSEMBLY Filed Oct. 9, 1956 INVENTOR. E HQE/,NE J- LEHMAN BY M4 l )2f/ca@ 3,021,502 APatented Feb. 13, 19,622

3,021,502 l f TERMINAL CONNECTOR AND GUARD ASSEMBLY EugeneJ. Lehman, Zanesville, Ohio, assgnor to Mc- Graw-Edison Company, a corporation of Delaware Filed Oct. 9, 1956, Ser. No. 614,905

Claims. (Cl. 339-202) This invention relates to' a terminal connector and guard assembly for use with electric distribution installations and has particular reference to an assembly for connecting the terminals of electrical apparatus such as a trans- Vformer bushing terminal to a power line and for preventing interruption of electrical service by animals and birds which may frequent the top of the transformer.

The invention, in general, is directedto an assembly including in a single unitary structure a bushing cap adapted to be secured to a terminal bushing, and an eye-bolt type connector to receive the power line lead. vThe connector and bushingL cap are enclosed by a protec .tive cup-shaped cover or shield Yhaving a suitable opening to vaccommodate an insulating knob for tightening the line lead within the eye-bolt connector. Circumferentially spaced ribs on the inside of the cover member support the cover mmeber on the bushing cap and serve to main tain it in position in service.

The acceptedindustry standards forV distribution transformers require that. the cover-type bushing provide vertical take-olf of the power line lead, and it is an object of the invention to provide an improved terminal connector and guard assembly wherein the power lead `may enter vertically as required by the accepted industrystandards, and a rotatable hand knob is provided for manual tightening of the line lead. v

The accompanying drawing illustrates the bestl modek presently rcontemplatedby the inventor for carrying out the invention.

In the drawing:

FIGURE 1 is a vertical sectional View of the terminal f connector and guard assembly of the invention;

FIG. 2 is a section taken on line 2-2 of FIGURE l.

FIG. 3 is a vertical sectional view of the protective guard or cover; and

FIG. 4 is a perspective view of the cap and eye-bolt as assembled.

The drawing illustrates a terminal connector andfguard assembly for use with bushings of electrical apparatus. The assembly includes a cap 1 formed ofan electrically conductive material which is secured tothe upper end of thetransformerbushing 2 or the like.` The cap 1 includes a generally circular flanged base 3 and an upstanding centralportion 4 which extends upwardly from the base 3. The lowerr central surface of cap 1 is provided with a threaded recess 5, and a bolt 6 which projects upwardly from the transformer bushing 2 is threadedly received -within recess 5 andk serves to secure the cap 1 to the transformer bushingZ. A suitable gasket 7 is disposed within recess 5 between upper end of the bushing and the-cap.

The upper end lof' the central portion 44 of cap 1 is provided with an embossment 8 which is formed with an opening 9 to receive the power line lead 10. u

. 2 attach the power line lead 10 to the cap by means of an insulating hand knob 17 which is threadedly engaged with `the outer end portion of the eye-bolt 11. The outer end portion of eye-bolt 11 is provided with an external thread 18 which is in threaded engagement with an internal thread 19 formed in the central insert 20 of knob 17. When the knob 17 is tightened, the head 13 of eye-bolt 11 is drawn inwardly towards the cap 1 to secure the power` line lead 10 against the cap 1.

To prevent rotation of the eye-bolt 11 whenA knob 17 is rotated, cap 1 is provided with a horizontal extending rectangular cavity 21, which receives the enlarged portion 14 of eye-bolt 11, and a pair of recesses 22 which communicate with cavity 21 and receive the end portions of the head 13 of the eye-bolt. The walls of the recesses 22 assure registry of the opening 15 in the eye-bolt with the conductor opening 9 in the cap. Whenv knob 17 is rotated, the ends of the head 13 engage the walls-of the recesses 22 to prevent rotation of the eye-bolt.

lt is a hazard to personnel on the ground for a lineman on a pole to drop a connector knob, or such mishap may require the lineman to descend the pole to retrieve the knob,y and in order to minimize the problem of the knob being completely lunthreaded from the eye-bolt 11, the external thread 18 in eye-bolt is interrupted by an unthreaded portion 23. Similarly, an internal thread 19 is interrupted by an Unthreaded portion 24. With this con.- struction, when the knob 17 is backed off the eye-bolt to release the power lead 10, a predetermined amount of unthr-eading will bring the unthreaded portion 23 into registry with the outer section of thread 19 and the unthreaded portion 24 into registry with the outer section of thread 18.' When this occurs, the knob 17 will turn freely to indicate to the operator that further unthreading should be avoided. With additional unthreading the knob 17 can be completely disengaged Afrom the eye-bolt 11. To provide this free rotation, the Unthreaded portion 23 of the eye-bolt must have a greater axial length than the outer section of internal thread 19. As the mechanical strength of the threaded connection is determined by the axial length of the internal thread, an increase in length of the outer section of thread 19 to increase the mechani- The bare end of the power line lead 10 is adapted to be secured to the cap 1 by an eye-bolt 11 which is disl onthe central portion 4 of the cap 1,.

nection is provided by a new arrangement in which the f internal thread 19 is divided into two sections separated by the Unthreaded portion 24. This construction increases the axial length of internal thread while minimizing the overall length of the eye-bolt.

An insulating guard 25 or cover is disposed over the cap 1 to protect the conductingportions of the apparatus from accidental contact from foreign objects. The guard 2S has a generally cup-shaped configuration lwith the open end of the guard facing downwardly toward the bushing 2. The upper end wall of the guard 25 is provided with an embossment 26, and an opening 27 is formed Vin the' embossment and receives the power line lead 10.` lf the power line'lead 10 is bare, an insulating sleeve, not shown, rcan bc disposed around the lead 10 and secured within the opening 27.k

Inaddition tothe opening Z7, the side wall ofthe guard i 25 is provided with an opening 28 to receive the knob 17, and a slot 29 is formed in the upper portion of the side wall of the guard inv registry with an electrodek 30 In embodiments wherein gapping yto auxiliary protection devices iS required the slot 29 provides the opening between electrode 30 and the cooperating electrode of the auxiliary device.

The lower end of guard 25 is spaced outwardly from the base 3 of cap 1 to provide a clearance 81 therebetween. The clearance 3l permits the drainage of moisture and other materials from the assembly.

The guard 25 is supported on the cap 1 by a series of internal ribs 32 which are provided on the inner surface of the guard and extend longitudinally thereof. The ribs 32 are circumferentially spaced and extend radially from the inner periphery of the guard toward the axis of the guard. Two adjacent ribs 32 are provided with depending projections 33 which are formed integral with the ribs and are adapted to contact the embossment S of cap 1 a-nd thereby prevent rotation of the guard 25 with respect to cap 1. In addition, the knob 17 which extends through the opening `28 in guard 2S also prevents rotation of the guard and thereby maintains alignment of the opening 27 in the guard and the opening 9 in the cap 1.

The llower end portion 34 of each rib 32 is decreased in depth to provide a shoulder 35 which rests on the base 3 and supports the upper end wall of the guard 25 in spaced relation with respect to the upper end of cap 1. In addition, the lower end portion 34 of the ribs extends within the clearance 3l and serves to space or center the lower end of the guard 25 on the base 3.

In addition to preventing rotation of the guard on the cap 1 and thereby maintaining alignment of the openings 27 and 9 for the reception of the power line lead, the ribs 32 function to space the guard both radially and vertically from the cap and also increase the stiffness and rigidity of the guard.

To increase the weather tightness of the assembly, a grommet-type plug, not shown, may be disposed within the opening 2,7 around the power line lead to prevent water or elements from leaking within the guard. In addition, a rain shield, not shown, may be disposed over the opening 28 to prevent leakage into the interior of the guard through this opening.

The present invention provides a simple and eicient combination guard and terminal connection assembly for electrical distribution apparatus. The power lead line may be conveniently secured to the cap by the rotation of knob 17 which is located on the outside of the guard so that neither the guard nor any other element of the assembly need be removed to affect the connection. This invention completely covers all live parts Iand assures continuity of service by preventi-ng short circuits caused by birds, animals and foreign objects.

The knob also serves to prevent rotation of the guard and thereby maintains alignment of the openings in the guard and the eye-bolt for convenient attachment of the power line lead.

The present invention also provides an indication to the operator when a predetermined degree of Unthreading has been elected between the eye-bolt and the knob. This tends to prevent the complete disengagement of the members.

The guard 25, which is composed of plastic or other insulating material, is of simple construction and the internal ribs serve to space the guard from the cap and provide addition-al stiffness and rigidity for the guard.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

l. An electrical terminal connection and guard assembly comprising, an electrically conductive cap having a base adapted to be secured to the terminal of a bushing and a central portion extending upwardly from the base with said central portion being provided with a transverse opening therein, an eye-bolt disposed Within said opening and having a head at one end thereof and an opening therein adjacent said head to receive a vertically extending electrical conductor, an insulating cover disposed around the cap and having an opening therein in alignment with the opening in said eye-bolt for passage of the electrical conductor to the eye-bolt, means associated with the internal surface of said cover and engageable with the base of said cap for supporting the cover in spaced relation to the cap, and means disposed externally of the cover and extending through a transverse opening in the cover for moving the head of said eye-bolt toward the cap to iirmly secure the conductor between the head and cap.

2. An electrical terminal connection and guard assembly comprising, an electrically conductive cap adapted to be secured to yan electrical terminal and having an opening therein, an eye-bolt disposed Within the opening in said cap and having a head at one end thereof and a vertically extending opening therein adjacent said head to receive a vertically extending electrical conductor, a hand knob threadedly engaged with the opposite end of said eye-bolt and adapted to be threaded on said eye-bolt to draw said head toward the cap and firmly secure the conductor between the head and cap, an insulating guard disposed around the cap and having openings to receive the electrical conductor and the knob respectively, and means connected to said guard and engaging the cap for preventing rotation of said guard with respect to said cap.

3. An electrical terminal connection and guard assembly comprising, an electrically conductive cap adapted to be secured to an electrical terminal and having an opening therein, an eye-bolt disposed within the opening in said cap and having a head at one end thereof and an opening therein adjacent said head to receive an electrical conductor, an insulating hand knob threadedly engaged with the opposite end of said eye-bolt and adapted to be threaded on said eye-bolt to draw said head toward the cap and firmly secure the conductor between the head and cap, an insulating guard disposed around the cap and having openings therein to receive the electrical conductor and the knob respectively, means connected to said guard and engaging the cap for preventing rotation of said guard with respect to said cap, and means associated with said last named means for supporting the guard on the cap.

4. An electrical terminal connection and guard assembly comprising, an electrically conductive cap having a base adapted to be secured to the terminal of a bushing and having a central portion extending upwardly from the base with said central portion being provided with a transverse opening therein, an eye-bolt disposed within the opening in said cap and having a head at one end thereof and an opening therein adjacent said head to receive an electrical conductor, a threaded member threadedly engaged with the opposite end of said eye-bolt and adapted to move said head toward the cap to firmly secure the conductor between the head and cap, and an insulating guard disposed around the cap and having openings therein to receive the electrical conductor and said knob and including a series of longitudinal ribs secured to the inner surface thereof, the lower end portion of said guard being spaced outwardly of the base of said cap to provide a clearance therebetween for the drainage of moisture from said assembly and said ribs being provided with shoulders spaced inwardly of the lower end of the guard and adapted to engage the base of said cap to support the guard in spaced relation with respect to the cap.

5. An electrical terminal connection and guard assembly comprising, an electrically conductive cap adapted to be secured to an electrical terminal and having a transverse opening therein, an eye-bolt disposed within the opening in said cap and having a head at one end thereof and an opening therein adjacent said head to receive an electrical conductor, a member threadedly engaged with the opposite end of said eye-bolt and adapted to draw the head of said eye-bolt toward the cap to firmly secure the conductor between said head and cap, means associated with the cap for engaging the head of the eye- `bolt and the opening in said guard.

6. A11y electricalV terminal connect-ion and guard as.`v

, around the cap and having openings to receive they elec-y trical conductor and the member respectively, and a plurality of ribs connected to the internal surface of the guard and including means for engaging the cap and preventing rotation of said guard with respect to said cap to` thereby maintain alignment of the opening in said eyesembly comprising, a cap formed of an electrically conductive material and adapted to ybe vsecured to anelectrical terminal, connecting means for removably securing *av Aan insulating guard disposed` power lead to the cap,

around said cap and having an end wall and a side wall, a series of ribs disposedon the inner surface of the side wall of said guard andv extendinglongitudinally fromV ceiving a vertical end portion of `a power lead, comprising a cap formed of electrically conductive material and havsaid end wall to the open'r end of said guard, said ribs being provided with shoulders disposed adjacent the open end of the guard and adapted to engage the cap and support the guard in spaced relation tothe cap, and means disposed externally of the guard and extending through an opening in said guard for actuating said connecting means to selectively connect and disconnect said power lead to the cap.

7. An electrical terminal connection and guardr a's-l sembly for transformers having a vertically projected electrical terminal extending fromy an insulating bushing comprising a cap `formed of electrically conductive material having a lead receive opening and adapted to be secured to the vertically projected electrical terminal with the lead receiving opening extending vertically, a lateral opening in said cap vertically spaced from the lead receiving opening, an eyebolt connector within said lateral open ing and having a horizontally extending threaded shank, an insulating guard cup disposed over said cap and having an opening in the end wall aligned with said lead receiving opening and a side opening in the sidewall aligned witlisaid lateral opening, and actuating means having an insulating portion exterior of the cap and extending through said side 'opening and being coupled to said threaded shank to selectively position said eyebolt con-l nector.

8. An electrical terminal connection and guard as sembly disposed at the terminal end of a vertically extending insulating Ibushing of an electrical transformer for receiving a vertical end portion of a power lead, coniprising a cap formed of electrically conductive material and having a horizontal opening therethrough, an insulatv ing guardcnp disposed over said cap and having an opening in Ithe end wall thereof for receiving the vertical end ing a horizontal opening therethrough and at least one kbifurcated portion adjacent said opening, an insulating guard cup disposed over said cap and having an opening in the end wall thereof for receiving .the vertical end por' tionof the incoming power lead, an eyebolt connector mounted within said horizontal opening in saidcap and hav-ing an eye for receiving said end portion of said power lead and having a threaded shank, said eyebolt connector having an extension disposed within the bifurcated portion of the capto prevent the connector from turning, said insulating guard cup having a second opening in another portion thereof for receiving said shank, and means including an insulating member disposed externally of said l cup and threadabiy engaging said shank for moving said eyebolt relative to said cap to clamp said end portion of said power lead between said eyebolt and said cap.

n 10. An electrical terminal connection and guard assembly disposed. at the terminal end of a vertically extending insulating bushing of an electrical transformer for receiving a vertical end portion of a power lead, comprising a cap formed of electrically conductive material and having a horizontal opening therethrough and having vertically extending biurcated portions with laterally extending aligned arms aligned on opposite sides of the opening, an insulating guard cup disposed over said cap and having an opening in the end wall thereof for receiving the vertical end portion of the incoming power lead, an eyebolt connector within said horizontal opening in said cap and having an eye for receiving said end'portion of said rpower lead and having integral verticalextensions on the end of the eyebolt :adapted to be disposed between the arms of therbifurcated portions to prevent turning of the eyebolt, said eyebolt connector having a horizontally extending shank with spaced threaded portions defining an unthreaded portion, said insulating guard cup having a second opening in another portion thereof for receiving said shank, and means including an insulating member disposed externally of said cup and having a pair of spaced threaded portions spaced generally in accordance with n the threaded portionsof the shank and threadably engagy, aligned with the opposite Unthreaded portions incident to portion of the incoming power lead, an eyebolt connector mounted within said horizontal openingin said cap and having an eye for receiving said end portionlof said power lead and having a threaded shank, said insulating guard cup having a second opening in ,another portion thereof adjacent said shank, and means including an insulating member disposed externally of said cup and threadably engaging said shank for moving said eyebolt relative to said cap to clamp said end portion of saidV power leadL between said eyebolt and said cap. y

9. An electrical terminal connection and guard assembly `disposed at the terminal end of a vertically extending insulating bushing of an electrical transformer for repredetermined outward movementof the` last named means. t y s l References Cited in the tile of this patent UNITEDVVSTATES PATENTS 516,341 Ayrton Vet al. v Mar. 2,018,672 Hill Oct. 29, 1935 2,234,662 Aime Mar. 11, 1941 2,636,065 Fiske Apr. 21, 1953 2,664,457 Ioublanc Dec. 29, 1953 2,672,595 Barr Mar. 16, 1954 2,740,100 Broverman Mar. 27, 1956 2,834,829 Broverman May 18, 1958 FOREIGN PATENTS 719 Great Britain of 1914 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,021,502 1 February 13, 1962 Eugene J Lehman y It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column l, line 25, for "mmeber" read member column 5, llne 30, for "receive" read receiving Signed and sealed this 12th day of June 192 (SEAL) Attest:

ERNEST w. SWIDER` DAVID L LADD Attesting Officer Commissioner of Patents 

